As is the case in any moving vehicle, an important factor in the smooth, safe and efficient operation of a railroad car is the condition of the wheel surface which engages the rails. This surface is originally machined within fairly close tolerances to a specific contour. This contour consists of a tread which gradually tapers outward from its axis from its tread edge to an outwardly extending flange which culminates in the flange edge of the wheel. This surface engages the rail in a manner which causes maximum wear in the transition area between tread and flange. Historically, worn railroad wheels have been reclaimed by machining the wheel to a new diameter at which there is sufficient material to restore the original contour. This process must be performed equally around the wheel tread circumference of both wheels in a set. There is of course minimum requirements for flange thickness and wheel diameter which limit the number of times a wheel can be reclaimed. In the process of machining a railroad wheel several dimensions and reference points on the wheel must be measured and located. Since the wheel turning lathes of the prior art are substantially manually adjusted, calipers and gages were provided which were to be manipulated and read by the operator. These readings would be used to set the starting point and depth of cut before the machining operation. Actual tool movement was controlled mechanically by a template corresponding to the desired contour. In general, calipers were provided on the machine which could be moved into contact with the tread surface and flange edge of the wheel, thereby ascertaining the actual worn diameter of the wheel and the location of the flange edge. According to normal procedure, a a gaging point is selected on the tread face of the flange. In general, this point is chosen at the location of maximum wear. A manual gage (A. A. R. steel wheel gage) as shown in FIG. 3 of the drawing described below is widely used to detemine the change in position of this gaging point or change in flange thickness from the original contour. By pivoting the movable finger shown in the manual gage into contact with the gaging point, the amount of change can be read. This distance is generally used to determine the depth of cut required to restore the contour.
Since it is desired to automatically control the movement of the lathe tool, a device is needed to automatically obtain these readings and convert them to a form which is readable by the automatic control system. It is, therefore, the purpose of this invention to provide such a gaging assembly.